The adage ''Every landing you walk away from is a good one and one where the aircraft is still flyable is a great one'' springs to mind.
A good outcome to a potential serious incident and I hope the chap in question continues with his training. I would imagine that he has learnt a lot from this in particular that normally gliders whilst committed to approach can't go around unless there is a pylon mounted engine. In hindsight I am sure he would concur that if engine power was still available that a go around with a right turn would have possibly been the better option. With that said considering his experience a go around with low level turn could have excaberated the situation leading to stall spin.
This is no way a criticism and I commend him for landing the aircraft with out injury and dealing with a situation that would probably disturb even the most experienced of aviators.
Regards MF26